Important limitations
- Individual claims and source links have not yet completed editorial verification.
- Evidence level, applicable study model, formulation, route and population remain unassigned.
Melanotan 2
Melanotan 2, also known as MT-2, is a synthetic analog of alpha-melanocyte-stimulating hormone.
Dosing & scaling, explained
The moderated mass amounts below are retained for comparison. Near-duplicates, mix-dependent volumes and device markings are excluded. This is educational source context, not a protocol or recommendation.
Mass amounts available for comparison
- Lower range50 mcgMaintenance Phase
Recorded example with no verified study backing; shown for amount literacy only.
- Low-mid range100 mcgMaintenance Phase
Recorded example with no verified study backing; shown for amount literacy only.
- Mid range300 mcgLoading Phase
Recorded example with no verified study backing; shown for amount literacy only.
Only mcg or mg amounts are retained. The calculator derives mL, syringe units or pen clicks from the current vial strength, water volume and device.
No independently verified schedule
Evidence context
No clinical amount or schedule is inferred from this material. Source verification is pending, and every displayed amount remains educational context rather than guidance.
Storage, handling and interpretation
Product identity
Verify the exact compound, formulation and amount against the product label or certificate before calculation.
Storage & handling
Follow the product label, certificate and validated laboratory SOP; no universal storage assumption is applied here.
Prepared solutions
Label concentration and preparation date, use sterile technique where applicable, and follow a validated stability protocol.
Reported protocols for Melanotan 2
What published studies and recent community write-ups report about amounts, timing and course length. 4 clinical and 4 community-reported rows, each linked to its source. These are descriptions of what others report, not instructions, and nothing here is medical advice.
| Context | Dose | Frequency | Route | Course | Source |
|---|---|---|---|---|---|
| Clinical4 rows | |||||
| Phase 1 pilot study, dose escalation3 healthy men at the University of Arizona | 0.01 mg/kg to start, escalated in 0.005 mg/kg steps to 0.025-0.03 mg/kg | Monday to Friday for 2 weeks, alternating MT-II and saline days (5 active doses in total) | Subcutaneous | 2 weeksNot applicable | Life Sciences (PubMed)1996 |
| Two of the three men showed measurable darkening of the face, upper body and buttocks a week after the last dose, from a cumulative exposure of only about 0.1 mg/kg. The 0.03 mg/kg dose caused grade 2 fatigue and somnolence in one man, mild nausea occurred at most dose levels, and stretching, yawning and erections lasting 1-5 hours followed dosing; the authors set 0.025 mg/kg as the dose for future studies. | |||||
| Psychogenic erectile dysfunction crossover trial10 men with erectile dysfunction of no known organic cause | 0.025 mg/kg (about 1.75 mg for a 70 kg man) | Single injection per session, MT-II and placebo on separate days | Subcutaneous | One monitored 6-hour session per treatmentNot applicable | Journal of Urology (PubMed)1998 |
| Eight of ten men developed clinically apparent erections, and mean time with tip rigidity above 80% was 38 minutes on MT-II against 3 minutes on placebo. Nausea, stretching and yawning and reduced appetite were more common after MT-II, though none needed treatment; the study was tiny and measured a single dose under laboratory monitoring. | |||||
| Organic erectile dysfunction crossover trial10 men with erectile dysfunction and organic risk factors | 0.025 mg/kg | Two MT-II and two placebo injections per man, each on a separate day | Subcutaneous | Four monitored 6-hour sessionsNot applicable | Urology (PubMed)2000 |
| Erections followed 12 of 19 MT-II injections versus 1 of 21 placebo injections, with 45 minutes of tip rigidity above 80% versus about 2 minutes, and self-rated sexual desire was higher after MT-II. Four of the 19 active injections produced severe nausea, which is why the more selective metabolite bremelanotide was pursued instead of MT-II. | |||||
| Overdose case report, internet-sourced productOne 39-year-old man self-injecting for winter tanning | 6 mg in a single injection (six times the vendor's starting dose, by his account) | Single dose | Subcutaneous | Single event, 3 days in intensive careNot applicable | Clinical Toxicology (PubMed)2012 |
| Within two hours he developed a sympathomimetic picture of tachycardia to 146 beats per minute, sweating, tremor and agitation, followed by rhabdomyolysis with creatine kinase peaking at 17,773 IU/L and acute kidney injury. Mass spectrometry confirmed the vial contained MT-II; the report illustrates what a milligram-scale overdose of an unregulated product can do. | |||||
| Community-reported4 rows | |||||
| Community loading ladder | 100-250 mcg daily (days 1-3), 250-500 mcg daily (days 4-14), then 500-1,000 mcg daily | Once daily during loading, usually at bedtime | Subcutaneous | 4-6 weeks of loading, with many frameworks capping loading at 8 weeks4-6 or more weeks off after a 4-8 week cycle; winter pauses with a reload before the next sunny season | Community resource2026 |
| This 2026 vendor-affiliated guide lays out a three-stage loading phase that only steps up when nausea and flushing stay manageable, then a maintenance phase of 500-1,000 mcg once or twice weekly (250-500 mcg when pigment is already strong). It notes that lighter skin types respond sooner and that none of these figures come from an approved label. | |||||
| Two-phase tanning course | 250-500 mcg (100-250 mcg to start if nausea-prone) | Daily for 2 weeks, then 1-2 times per week | Subcutaneous, before bed | 2-week loading phase, then open-ended maintenanceNone described; tan reported to persist for weeks to months after stopping | Community resource2026 |
| A calculator site's 2026 page gives the reconstitution math (10 mg in 2 mL gives 5 mg/mL, so 250 mcg is 5 units on a U-100 syringe) and describes brief UV exposure as enhancing the response. It flags mole darkening as a monitoring problem rather than a feature and rates the compound as low-evidence. | |||||
| Reference-site summary of community practice | 0.25-0.5 mg during loading; 0.5-1 mg for maintenance; 2 mg described as a single-dose ceiling | Daily or alternate days for 2-3 weeks, then once or twice weekly | Subcutaneous, abdomen or thigh | 2-3 weeks of loading, then maintenanceNone described | Community resource2026 |
| This 2026 reference page contrasts the trial dose of 0.025 mg/kg (about 1.75 mg) with the much smaller daily amounts used for tanning and records the April 2026 removal of MT-II from the FDA's compounding Category 2 after the nominators withdrew. It stresses that no dose range has been validated in a regulated trial. | |||||
| Low-dose titration protocol | 100-250 mcg daily to load; 50-100 mcg every 2-3 days to maintain | Daily for 1-2 weeks, then every 2-3 days | Subcutaneous | 1-2 weeks of loading, then ongoing maintenanceNone described | Community resource2025 |
| A vendor-linked protocol page from 2025 uses far smaller maintenance doses than most guides, keeping injections at 1-5 units of a 5 mg/mL solution. It lists nausea, erections, blood pressure effects and new or changed moles as the expected downsides and cites only the two original Arizona papers. | |||||
How a course is commonly described
- Days 1-3: assessmentCommunity-reported
Community guides start at 100-250 mcg a day, injected before bed so that the nausea and flushing peak during sleep. The first few doses are described as a tolerance check rather than a tanning dose, and spontaneous erections in men commonly appear from the first injection.
- Weeks 1-2: loadingCommunity-reported
Doses step up to 250-500 mcg daily. Guides describe gradual darkening beginning in this window, with nausea most frequent here and freckles and existing moles often darkening before the overall skin tone changes.
- Weeks 3-6: standard loadingCommunity-reported
Some frameworks continue at 500-1,000 mcg daily until the target pigment is reached, often coordinated with short UV sessions. Loading is usually capped at 6-8 weeks because long-term controlled safety data do not exist.
- Maintenance and breakCommunity-reported
After loading, 0.5-1 mg once or twice a week is described as holding the tan, dropping to 250-500 mcg weekly or less when UV exposure is regular. Many users pause entirely over winter and reload the following season; a 4-6 week break after a 4-8 week cycle is the usual convention.
- Clinical comparisonClinical
The only formal course ever studied was two weeks of alternating-day injections at 0.01-0.03 mg/kg in three men, which produced visible tanning from just five active doses. The erectile dysfunction trials used single 0.025 mg/kg doses, roughly three to seven times the daily community loading dose, and caused severe nausea in about one injection in five.
- No multi-week MT-II course has ever been tested in a controlled trial. The community loading and maintenance schedules are vendor and forum conventions built on a 1996 pilot in three men and on the single-dose erectile dysfunction studies.
- Published case reports link MT-II use to darkening and eruption of moles, melanoma arising in existing moles, priapism needing surgical decompression, rhabdomyolysis after a 6 mg injection and posterior reversible encephalopathy syndrome. The FDA cited these events when it placed the peptide in compounding Category 2 in 2023; the nomination was withdrawn in April 2026, which removed the designation without creating a lawful compounding pathway.
- Products sold online as Melanotan II are unregulated. One toxicology report had to confirm the vial's identity by mass spectrometry, and dermatology reviews note that preparation, dose and sterility are all unknown to the buyer. The rows above record what sources report, not endorsements of use.
Sources for this section (11)
- Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study
- Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study
- Effect of an alpha-melanocyte stimulating hormone analog on penile erection and sexual desire in men with organic erectile dysfunction
- Melanotan II injection resulting in systemic toxicity and rhabdomyolysis
- Risks of unregulated use of alpha-melanocyte-stimulating hormone analogues: a review
- Melanotan Tanning Injection: A Rare Cause of Priapism
- Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks
Plus 4 community resources (dosing guides, forum threads and vendor write-ups), reported above but not linked.
How Melanotan 2 is being studied to work
This process map organizes available educational context. Individual claims remain subject to source-level verification.
- 1
Melanotan 2 and Melanocortin Signaling
Understanding MT-2's receptor binding and signaling mechanisms
Overview
Melanotan II (MT-II) is a synthetic, cyclic seven-residue analog of the pigment hormone alpha-MSH, designed at the University of Arizona in the late 1980s as a way to induce a protective tan without ultraviolet exposure. It activates several melanocortin receptor subtypes at once, so alongside skin darkening it produces nausea, flushing, appetite suppression and spontaneous erections, the last of which led to the small erectile dysfunction trials of the late 1990s and to the development of its metabolite bremelanotide. Human data consist of a three-person phase 1 pilot, two ten-man crossover studies and a growing stack of case reports; MT-II has never been approved anywhere, is sold illegally for tanning, and was listed by the FDA among compounding substances that may present significant safety risks from 2023 until the nomination was withdrawn in April 2026.
What researchers are exploring
These themes organize the educational information currently available. Individual claims remain under source review and are not treatment claims.
- 1
Melanotan 2 and Melanocortin Signaling
Understanding MT-2's receptor binding and signaling mechanisms
- 2
Melanotan 2 and Autism
MT-2's potential in treating Autism Spectrum Disorder
- 3
Melanotan 2 and Appetite Control
MT-2's role in appetite suppression and weight management
- 4
Melanotan 2 and Diabetes
MT-2's potential in diabetes treatment and blood sugar regulation
- 5
Melanotan 2 and Impulse Control
MT-2's role in reducing addictive behaviors and alcohol consumption
- 6
Melanotan 2 and Erectile Dysfunction
MT-2's efficacy in treating erectile dysfunction and sexual desire disorders
What is known and what still needs verification
Available context is organized without assigning unsupported study models or evidence grades.
- Not graded
Melanotan 2 and Melanocortin Signaling
Understanding MT-2's receptor binding and signaling mechanisms
- Not graded
Melanotan 2 and Autism
MT-2's potential in treating Autism Spectrum Disorder
- Not graded
Melanotan 2 and Appetite Control
MT-2's role in appetite suppression and weight management
Amounts recorded for Melanotan 2
These amount records are independent from vial strength, reconstitution volume and measuring device. A recorded source is not the same as study backing, and these values are not recommendations.
- 1Maintenance Phase · lower endpointSign in for schedule, duration and source context.50 mcg
- 2Maintenance Phase · upper endpointSign in for schedule, duration and source context.100 mcg
- 3Loading Phase · upper endpointSign in for schedule, duration and source context.300 mcg
Chemistry identifiers
Sequence, synonyms and registry identifiers as recorded in PubChem, the National Library of Medicine's open chemistry database. Formula, mass and CAS number are summarized at the top of the page.
Sequence
Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2
Also listed as
Melanotan II, MT-II, MT-2, Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, UNII UPF5CJ93X7, CHEMBL430239, CHEBI:195326, GTPL1323
InChIKey
JDKLPDJLXHXHNV-MFVUMRCOSA-N
IUPAC name
(3S,6S,9R,12S,15S,23S)-15-[[(2S)-2-acetamidohexanoyl]amino]-9-benzyl-6-[3-(diaminomethylideneamino)propyl]-12-(1H-imidazol-5-ylmethyl)-3-(1H-indol-3-ylmethyl)-2,5,8,11,14,17-hexaoxo-1,4,7,10,13,18-hexazacyclotricosane-23-carboxamide
Limitations and unknowns
Sources
1 link carried over from the earlier page, awaiting verification.